Clinical experience and psychometric properties of the Children's Dermatology Life Quality Index (CDLQI), 1995-2012

The Children's Dermatology Life Quality Index (CDLQI) is a widely used questionnaire to measure the quality of life of children aged from 4 to 16 years. The purpose of this review is to summarize all published data regarding the clinical experience of the CDLQI and its psychometric properties as a single reference source for potential users. A literature search was carried out to identify all articles describing the use of the CDLQI from 1995 to November 2012. One hundred and six articles were identified, with four excluded. The CDLQI has been used in 28 countries in 102 clinical studies and is available in 44 languages, including six cultural adaptations; a cartoon version is available in 10 languages. It has been used in 14 skin conditions and used in the assessment of 11 topical drugs, nine systemic drugs, 13 therapeutic interventions and two epidemiological and other studies. There is evidence of high internal consistency, test-retest reliability, responsiveness to change, and significant correlation with other subjective and objective measures. Rasch analysis has not been carried out and more information is needed concerning minimal clinically important difference; these are areas requiring further study.

Infants' Dermatitis Quality of Life Index: a decade of experience of validation and clinical application

The Infants' Dermatitis Quality of Life Index (IDQoL) is a questionnaire completed by parents to assess the impact of atopic dermatitis on the quality of life of infants aged 0-3 years. The aim was to review all clinical and psychometric data on the use of the IDQoL from its inception in 2001 until November 2012, to serve as a single reference source. A literature search was carried out using Medline, PubMed, EBSCOhost, Science Direct and Google Scholar. Articles and abstracts that described the clinical use of the IDQoL and those that investigated its psychometric properties were included. Articles not in English were excluded. Fifty-one publications were identified, of which 46 fulfilled the inclusion criteria. IDQoL data relating to psychometric, descriptive and clinical practice research, drug trials and therapeutic interventions were extracted. The IDQoL has been translated into 21 languages and used in 18 countries, including two multinational studies. Thirty-one studies demonstrated its psychometric properties, such as test-retest reliability, internal consistency, validity, responsiveness to change and interpretability. No studies investigated dimensionality, carried out factor analysis or described the minimal clinically important difference of the tool. Eight studies used the IDQoL to assess the effectiveness of therapeutic interventions such as education programmes, consultations and wet-wrap therapy, while seven studies described the use of IDQoL in topical interventions. When deciding whether to use the IDQoL, researchers and clinicians should consider the validation data, the relevant comparative clinical data available and the potential burden on the respondents.

Measurement of health-related quality of life in dermatological research and practice: outcome of the EADV Taskforce on Quality of Life

In the last decade, the importance of the measurement of health-related quality of life (HRQoL) has grown significantly. Today, HRQoL measurement is generally considered to be important in clinical trials, in the assessment of disease severity, in patient management and in the field of health economics. Therefore, a good understanding of the concept of HRQoL and its measurement instruments is a prerequisite for both researchers and clinicians. The European Academy for Dermatology and Venereology (EADV) Taskforce on Quality of Life encourages the application of HRQoL instruments in research and clinical practice, and with this manuscript, the Taskforce aims to contribute to the quality of this application. In dermatology, a large number of HRQoL instruments exist and herewith, we summarize the most commonly used generic and dermatology-specific HRQoL instruments. Information is given on the most important psychometric characteristics of these instruments, including: scale structure, reliability, validity and responsiveness. Furthermore, a flow chart is provided to support researchers and clinicians in selecting an existing instrument or, in case an appropriate instrument does not exist, in finding alternative solutions. The present manuscript is the first of a series of manuscripts to be written on behalf of the EADV Taskforce on Quality of Life, aiming to contribute to the scientific knowledge and measurement of patient reported outcomes in dermatological research and practice.

Psychometric properties of the Chinese version of Dermatology Life Quality Index (DLQI) in 851 Chinese patients with psoriasis

BACKGROUND

The Dermatology Life Quality Index (DLQI) is one of the most frequently used scales to evaluate the impact of skin disease on patients' quality of life (QoL). There has not been psychometric evaluation of the Chinese version of DLQI in Chinese patients with psoriasis.

OBJECTIVE

The objective of this study was to evaluate the psychometric properties of the Chinese version of DLQI.

METHODS

Patients with psoriasis (≥ 18 years old) visiting nine hospitals in various regions of China were enrolled in the study. The DLQI, Psoriasis Disability Index (PDI) and Health Survey Short Form (SF-36) were completed. Severity of psoriasis was assessed by the Psoriasis Area Severity Index (PASI). Reliability was estimated by internal consistency. Validity was assessed using known-groups comparison, convergent validity and construct validity.

RESULTS

In all, 851 patients were included in the study. The internal consistency reliability of the DLQI was high (Cronbach's alpha = 0.91). Known-groups comparison showed that the DLQI discriminated well among patients who differed in age, geographical region, duration of psoriasis and the PASI score. Evidence of convergent validity of the DLQI was proved by high correlations with the PDI and four subscales of SF-36 (role-physical, bodily pain, social functioning and role-emotional): r = 0.52-0.78. Construct validity was proved by the presence of one-factor structure that accounted for 55.9% of the variance and fitted well into the unidimensional model.

CONCLUSION

The Chinese version of DLQI is a reliable and valid measure to assess patient-reported impact of skin disease and could be used in QoL and health outcome studies on Chinese psoriasis patients.

Nonclinical influences, beyond diagnosis and severity, on clinical decision making in dermatology: understanding the gap between guidelines and practice

BACKGROUND

Clinical decision making in dermatology is a complex process and might be influenced by a wide range of nonclinical factors.

OBJECTIVES

The aim of this study was to explore the role of nonclinical influences, beyond diagnosis and severity, on clinical decision making in dermatology.

METHODS

Semi-structured qualitative interviews were conducted with 46 clinicians working in departments of dermatology of nine different hospitals in Wales. Interviews were audio-recorded and later transcribed and their contents analysed.

RESULTS

Nonclinical factors influencing patient management decisions in dermatology that were identified related to patients, clinicians and practice characteristics. Patient-related factors included place of residence, socioeconomic circumstances, education and intelligence, ethnicity, age, treatment adherence, expectations from treatment, quality of life, concerns and worries, difficult patients, and family members or friends. Clinician-related factors included time constraints in clinic, clinicians' personal circumstances, relationship with colleagues, and relationship with pharmaceutical companies. Practice-related factors included working in private practice, cost of treatment to the National Health Service (NHS), prescribing bureaucracy, and availability of treatment service in the work place. There was a difference between the consultants' views and those of the other clinicians over the impact of pharmaceutical companies on clinicians' prescribing and the awareness of treatment costs to the NHS. Most of the factors identified could potentially influence the clinicians' decision-making process subconsciously. Some clinicians highlighted that these factors are untaught in the medical curriculum, and are usually ignored in clinical guidelines, and therefore represent a challenge to the practice of evidence-based medicine.

CONCLUSIONS

This study has described one aspect of the reality of medical decision making beyond the conventional evidence-based guidelines approach. Proper understanding of nonclinical influences on decision making is of paramount importance for the best patient-centred treatment outcomes.

Non-clinical influences on clinical decision-making: a major challenge to evidence-based practice

This article reviews an aspect of daily clinical practice which is of critical importance in virtually every clinical consultation, but which is seldom formally considered. Non-clinical influences on clinical decision-making profoundly affect medical decisions. These influences include patient-related factors such as socioeconomic status, quality of life and patient's expectations and wishes, physician-related factors such as personal characteristics and interaction with their professional community, and features of clinical practice such as private versus public practice as well as local management policies. This review brings together the different strands of knowledge concerning non-clinical influences on clinical decision-making. This aspect of decision-making may be the biggest obstacle to the reality of practising evidence-based medicine. It needs to be understood in order to develop clinical strategies that will facilitate the practice of evidence-based medicine.

Adolescents with skin disease have specific quality of life issues

BACKGROUND

Adolescence is a period of life with its own unique characteristics.

OBJECTIVES

To provide an in-depth understanding of the impact of skin disease on different aspects of adolescents' health-related quality of life (HRQoL).

METHODS

Semi-structured qualitative interviews were conducted with a sample of dermatology patients between 12 and 19 years of age, attending the dermatology outpatient clinic of a secondary referral centre. Participants were invited to talk in detail about all the ways their lives had been affected by their skin disease. Interviews were transcribed verbatim.

RESULTS

Thirty-two adolescents (males = 10, females = 22) with a mean age of 15.7 years (range = 12-18 years) participated in the interviews. Twenty-eight HRQoL themes adversely affected by skin diseases were identified from the interviews which were grouped under 6 main HRQoL domains - psychological impact (91% of patients), physical impact (81%), social impact (81%), impact on lifestyle (63%), need for support (41%) and education and employment (34%). The number of HRQoL themes affected in each individual varied between 1 and 23 (mean = 8.1).

CONCLUSIONS

The results of this study revealed the extent and nature of the impact of skin diseases on adolescents' HRQoL. A number of issues identified were specific to adolescents, highlighting the need for specific HRQoL assessment.

The Dermatology Life Quality Index 1994-2007: a comprehensive review of validation data and clinical results

BACKGROUND

The Dermatology Life Quality Index (DLQI) is one of the most widely used dermatology-specific quality of life instruments. Over the last 5 years there has been great interest in its use.

OBJECTIVES

To collect and present all information regarding the technical properties and the clinical use of the DLQI from the date it was published to the end of 2007 for use as a single source of reference.

METHODS

A detailed literature search was conducted using electronic reference databases and the DLQI library in the Department of Dermatology, Cardiff University. All publications mentioning any aspect of the DLQI, from the time of its development to the end of 2007, were identified and the data concerning the DLQI in terms of its psychometric analysis, and use in clinical trials, epidemiological studies and health services research, were extracted and tabulated with all the relevant references.

RESULTS

In total, 272 full articles which have included the DLQI were reviewed. Studies described in these articles were divided into five main categories: psychometric studies, descriptive/epidemiological studies, drug (topical and systemic) trials, clinical practice research, and therapeutic interventions. The DLQI has been used in 33 different skin conditions in 32 countries and is available in 55 languages. Psychometric aspects of the DLQI such as validity, reliability, responsiveness to change, factor structure, and minimal important difference were described in 115 studies. The DLQI has been used in 33 studies assessing the effectiveness of 14 different types of therapeutic interventions and in 37 studies evaluating nine types of clinical practice research. Sixty studies have used it alone or in parallel with other instruments as an outcome measure in clinical trials of 18 systemic drugs while 22 studies have used it in 14 different topical drug trials. The DLQI has also been used in 27 multinational studies.

CONCLUSIONS

During the last 14 years there has been a gradual increase in the international use of the DLQI. The brevity and simplicity of use of the DLQI has resulted in its popularity both in clinical practice and in research. However, there are various issues in particular regarding its unidimensionality, differential item functioning, and minimal clinically important difference, which require further research. This article should facilitate the work of potential users of the DLQI by providing a readily available source of references for different aspects of the DLQI.

The family impact of skin diseases: the Greater Patient concept

BACKGROUND

Although the impact of skin disease on patients' health-related quality of life (HRQoL) is well known, little work has been carried out to determine the secondary impact of a patient's skin disease on the patient's family or partner.

OBJECTIVES

The aim of this study was to identify the different aspects of a family member's QoL that may be affected by having a family member with skin disease.

METHODS

Qualitative interviews were conducted with 50 family members/partners of patients attending the outpatient clinic of a university hospital, with a wide range of dermatological conditions (n = 21). Subjects were invited to discuss in detail all the ways that their lives were affected by living with a patient with skin disease.

RESULTS

The mean age of subjects (M = 19; F = 31) was 48.1 years (SD = 15.7) most were either parents (44%) or spouses/partners (44%) of the patients. Patients' ages (M = 16; F = 34) ranged from 5 months to 84 years. Fifty-nine aspects of QoL of family members were identified that were adversely affected by the patients' skin disease. These were categorized into 18 main topic areas: Emotional distress (98%), Burden of care (54%), Effect on housework (42%), Social life (48%), Holidays (46%), Financial aspect (30%), Physical well-being (22%), Job/study (40%), Leisure activities (26%), Sleep (20%), Food/drink (12%), Restriction of liked activities (14%), Need for support (12%), People's attitude (10%), Dissatisfaction with medical care (14%), Effect on sex life (8%), Role of religious faith (8%) and Miscellaneous (16%). There was no significant difference between male and female subjects regarding main QoL areas affected. The median number of main topic areas reported per family member was five (mean = 5.2, range = 1-10, SD = 2.64).

CONCLUSIONS

This study has demonstrated that skin diseases can significantly impair the HRQoL of the patient's family in very diverse ways. Asking family members about this impact is greatly appreciated by them. We propose the 'Greater Patient' concept to describe the immediate close social group affected by a person having skin disease.

The Family Dermatology Life Quality Index: measuring the secondary impact of skin disease

BACKGROUND

Skin diseases are known to have a major impact on the lives of patients and their families. Many instruments are available to measure the health-related quality of life (HRQoL) of patients but no measure has been developed so far to quantify the secondary impact on family members of the patients.

OBJECTIVES

To develop and validate a dermatology-specific instrument to measure the adverse impact on the HRQoL of family members of patients with skin disease.

METHODS

Detailed semi-structured interviews were conducted with family members of patients to identify different aspects of HRQoL affected. An initial draft version of the questionnaire based on the main topic areas was pilot tested to assess the face and content validity. A 10-item questionnaire, the Family Dermatology Life Quality Index (FDLQI), was finalized after modifications to the draft questionnaire based on feedback from families and dermatology professionals and on item reduction. Psychometric evaluation was conducted on a new cohort of family members (n = 132) who completed the FDLQI and the patients (n = 109) who completed the Dermatology Life Quality Index (DLQI).

RESULTS

Fifty-nine different aspects of family members' HRQoL were identified from the analysis of the interviews, which were categorized into main topic areas. Factor analysis of 10 items of the final questionnaire revealed two factors and together these explained 60% of the common variance. The FDLQI demonstrated high internal consistency (Cronbach's alpha = 0.88) and test-retest (intraclass correlation coefficient = 0.94) reliabilities. The responsiveness of the instrument to change was shown by significant change in the family members' FDLQI scores in cases where patients' clinical condition either improved or worsened. Construct validity was assessed by testing a number of a priori hypotheses. A strong correlation was seen between the family members' FDLQI scores and patients' DLQI scores (r = 0.69), a significantly higher FDLQI score was seen for inflammatory skin diseases compared with noninflammatory diseases/isolated lesions (P < 0.0001), and there was a positive relationship between the family members' FDLQI scores and patients' disease severity (r = 0.49).

CONCLUSIONS

The FDLQI is simple and practical and seems to have the potential to be used as an additional outcome measure in clinical practice and evaluation research.